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Hey guys just failed smogg and sure what else to check. I have high HC and CO
My cat was new 2 years ago but it looks like its barely doing its job now. Its a magnaflow CA legal cat.
i did a full tune up, the timing is top dead center, idle rpm is at 750ish, all fluids replaced and replaced O2 sensor recently too. Acv seems to be working well. I checked the purge hose. Air dumps out at about 3,500 rpm
Those aftermarket cats leave a lot to be desired. Years ago on the daughter's Maxima, replaced a cat and the car passed inspection, 7 months later the CEL came on, same converter, so just used spark plug non foulers and passed for the next 3 years, but here in Jersey, no tailpipe reading, they just check for a CEL.
You wrote: "...timing is top dead center...". Not sure if it matters, but ignition timing specs are Leading 5 deg ATDC and Trailing 20 deg ATDC at idle.
How are your spark plug wires?
How long have you owned this car? How many previous CA emissions tests have you passed?
I'm the original owner of a 90 RX7 GXL. A couple years after I bought the car, I had problems passing the VA emissions test, which is required every two years. I'd replace the cat and would squeak by the test. The next time, I would fail again. I then changed the ECU and never again had problems passing the test. Of course, now I no longer need to test because in VA it's no longer required after 25 years.
You wrote: "...timing is top dead center...". Not sure if it matters, but ignition timing specs are Leading 5 deg ATDC and Trailing 20 deg ATDC at idle.
How are your spark plug wires?
How long have you owned this car? How many previous CA emissions tests have you passed?
I'm the original owner of a 90 RX7 GXL. A couple years after I bought the car, I had problems passing the VA emissions test, which is required every two years. I'd replace the cat and would squeak by the test. The next time, I would fail again. I then changed the ECU and never again had problems passing the test. Of course, now I no longer need to test because in VA it's no longer required after 25 years.
I replaced the motor 2yrs ago. Motor now has 45,000miles. The compression was 120 on both rotors when motor was bought. I put about 15,000miles in 2 years.
I replaced the wires a month ago with new ngk. The o2 sensor was replaced 2 weeks ago. Maybe I have the timing off. I have an adjustable timing light. I leave it at 0° on the gun then connect it to L1. I align pin to the leading mark Yellow line. Then connect it to T1 and should automatically align the Trailing Red mark which it does. I always leave the gun on 0° and I think is the correct procedure.
Also could a bad temperature sensor be sending the wrong signal to the ECU? The car was fully warmed up. My temp gauge showed the needle at the half way point. When fully warmed up.
There should not be a need to ever mess with the timing. It's not routine maintenance to adjust it. An old trick is to fill up with premium fuel and a bottle of dry gas. Drive the car for a day and then go get the emissions test. Something about the dry gas burns cleaner and can help with emissions testing. I've never used that trick as we have no emissions testing where I live but I've heard of guys doing it for years.
A variation I've used successfully several times here in CO is to run your tank as empty as you dare and pour in a few gallons of denatured alcohol.
My testing station has a gas station right next door, so I only need drive a few feet to fill up with real gas after passing the test.
I agree with RXSpeed16's comment. Make sure that your car has completely warmed up before performing emissions test. Mazda had a TSB about making sure the cars are completely warmed up prior to emissions testing.
On another note, cats are usually warrantied for only 10 years. So, in your case they most likely need to be replaced.
I replaced the water temperature sensor. The one behind the water pump just to make sure its working properly since I never replaced it. I also replaced the connector since it was dry and falling apart. This is the key to on position reading from the connector. I think its suppose to be at about 5 volts
Drove the car and i got 230 miles with about 17 gallons.
120 miles highway driving and the rest is city driving.
Does this sound fine on the n/a rx7?
What I need to do is check for leaky injectors, but the previous owner said he had them cleaned at a shop.
Then check the map sensor with a vacuum to check fuel pressure
I replaced the water temperature sensor. The one behind the water pump just to make sure its working properly since I never replaced it. I also replaced the connector since it was dry and falling apart. This is the key to on position reading from the connector. I think its suppose to be at about 5 volts
Drove the car and i got 230 miles with about 17 gallons.
120 miles highway driving and the rest is city driving.
Does this sound fine on the n/a rx7?
What I need to do is check for leaky injectors, but the previous owner said he had them cleaned at a shop.
Then check the map sensor with a vacuum to check fuel pressure
That's about 14 mpg mixed city/hwy. I'd say that's not terrible, but it's slightly on the low side. It really depends on both your driving style and road/weather conditions.
I just filled up my tank and got about 15 mpg mixed city/hwy, but its been cold here in northern VA. Cold weather will affect your mpg. I'll usually get about 18 mpg city/hwy in the summer and about 22-24 mpg highway in the summer. I have gotten about 26 mpg hwy cruising along at about 70-75 mph on flat road. On the other hand, foot to the floor hwy driving will pull hwy mpg down to less than 20 mpg.
I agree with not heating it up enough. Also if it is definitely hot enough then your cat is dead. You've done everything else.
Edit: Have you flooded even once on that oil change? Clean oil makes a big difference.
I've never flooded it and the oil was recently changed.
I found out that the acv plunger was dry and not working 100% at all times. Replaced the ACV with a working one. Unfortunately i think the cat burned out since the proper air was not getting injected in the last year and a half. 😩 what cat would people recommend thats California legal?
01-01-20, 01:13 AM
